..to begin with: it was not a crappy movie at all..(canadian, i guess..from 2000 or 2001)

plot (..as far as i can remember..):a young couple (the guy was a biology or medicine student) went on a camping trip. on the road they were pickin up an hitchhiker who has got an infected arm with an obscure virus or virus-creature with thorns. he threatened the couple. then they drove to a gas station where the hitchhiker has to amputate his arm because this obscure virus is growing and growing. in the meantime, the biology student finds out that the virus can not survive in colder temperatures..then a much bigger virus-creature comes from the surroundings to the gas station..